0844 numbers

Hi.Any ideas, I feel a fool !I have a 0844 number that links to my home phone and can't find out what company gave it to me. They play music for a few seconds on the phone when you call me and I have had PRS threatening me with action unless I take it of, but can't as I don't have details, ???

PRS = Performing Rights Society who are becoming an aggressive pain over music being played by radio or anything which the public can hear. I can understand that they want musicians to have their royalties but they care causing upset.